On Mon, Apr 11, 2022 at 03:59:05PM +0900, Wangseok Lee wrote: > driver_init() -> > -> platform_dma_configure() / platform.c > |-> of_dma_configure() > |-> of_dma_configure_id() > :Here, set dma of 33+ address. > dma_set_mask(0xf`ffff`ffff), bus_dma_limit(0xf`ffff`ffff) Where do we set a large than 32-bit dma mask here? I can't find the code, and if there is we need to fix it. In Linux devices to come up with 32-bit DMA masks for historical reasons (they really should with a zero dma mask, but it is probably to lte to fix it). > -> artpec8_pcie_probe() / artpec-8 pcie driver code > |-> dw_pcie_host_init() / pcie-designware-host.c > |-> dma_set_mask(32) > : Here, set the dma mask of 32 addresses. > |-> dma_map_single_attrs() > |-> dma_map_page_attrs() > |-> dma_direct_map_page() > : Error return occurs here. > dma address has 33+ address and > dma bus limit is 33+. > However, this is because the mask value > has 32 addresses. If the dma_mask is set to 32-bits, we should never generate a large dma address, but bounce if it would othewise generate a larger address. That being said I think this code would be much better off using dma_alloc_coherent anyway. > Therefore, the dma_set_mask(32)(in dw_pcie_host_init()) > was modified to be performed only when > the dev-dma_mask is not set larger than 32 bits. So what sets dev->dma_mask to a larger than 32-bit value here? We need to find and fix that.
